title: Evidence for mobilization of intracellular calcium during the contractile response of the rat aorta to U44069.
abstract: The aim of the present investigation was to elucidate the pharmacological mechanism by which U44069, a stable PGH2 analogue, contracts the rat aorta. The results obtained demonstrate that while the contractile effect of potassium chloride is obliterated by removal of extracellular calcium, a substantial proportion of the contractile effect of U44069 persists under these conditions. The persistent effect of U44069 under calcium-free conditions was not diminished by nifedipine (a slow calcium channel blocker) but was blocked by 2-n-butyl-3-dimethylamino-5,6-methylenedioxyindene (an intracellular calcium antagonist). These results provide experimental evidence for the proposal that U44069 contracts the aorta in the absence of extracellular calcium by mobilizing intracellular calcium.
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D004533:Egtazic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D014662:Vasoconstrictor Agents
chemical_list: D011450:Prostaglandin Endoperoxides, Synthetic; D014662:Vasoconstrictor Agents; D004533:Egtazic Acid; C028429:U 44069; D002118:Calcium